Arenaria paludicola

Marsh sandwort, marsh sandwort, marsh sandwort

Family: Caryophyllaceae · Type: perennial · Native

Conservation status: CNPS 1B.1 · Endangered

Marsh sandwort is a rare (CNPS 1B.1) California native perennial found in southern Central Coast areas including Nipomo Mesa in San Luis Obispo County and the Santa Ana River region, growing in wet meadows and marshes at elevations below 300 meters. Flowering from late spring to summer, this plant produces delicate white flowers about 5 to 6 millimeters long, typically emerging singly from leaf axils. Growing with slender stems 25 to 90 centimeters tall, the plant is often supported by nearby vegetation and features distinctively angled or grooved stems that are shiny and mostly hairless. Its leaves are narrow and lance-shaped, measuring 20 to 55 millimeters long and typically 2 to 7 millimeters wide, with a single prominent vein. The plant produces approximately 15 to 20 dark brown, widely kidney-shaped seeds that are less than one millimeter long.

Habitat: Wet meadows, marshes

Bloom period: Late spring-summer

Elevation: < 300 m

Bioregions: s CCo (Nipomo Mesa, San Luis Obispo Co.), SnFrB (extirpated), SCo (Santa Ana River)

California counties: San Luis Obispo, San Bernardino, Santa Cruz, Los Angeles, San Francisco, Mendocino

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.